Stoker



INVENTOR llLMossl'lnr BY c3405 (Rm/a,

ATTORNEY Nov. 10, 1931. D. J. MossHART STOKER Filed JuneA 6, 1928 2 Sheets-Sheet 1 WITNESS L? Nov. 10, 1931.

5D. J. MossHART STOKER Filed June 6. 1928 2 Sheets-Sheet 2 INVENTOR D-Mosshcu-T WITNESS- BY 0,. (RWAa l ATTORNEY Patented Nov.. 10, 1931 UNITED STATES PATENT ori-"ICE" IIJONALD J. MOSSHART, OF LAN SDOWNE, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUS'E ELECTRIC `&' MANUFACTURING COMPANY, A CORPORATION 0F PENNSYLVANIA.

, STOKEB,

Application iiled June 6,

rThis invention relates to untlerfeed stokers, and particularly to underfeed stokers having substantially horizontally arranged retorts and fuel supporting surfaces arranged laterally of the retorts; and 1t has for an object to provide an apparatus of th1s character which is of improved construction' and arrangement of parts.

In general, an apparatus of this character comprises a horizontally arranged retort which receives fuel through one end'thereof land discharges the fuel over the sides thereof, a fuel supporting grate surface extendinglaterally from the upper edges of the s ide. 'Wall of the retort, a prlmary fuel feedlng this character heretofore known to me, for

the reason that different kinds of fuel have different feeding characteristics. Heretofore, a stoker which was designed to operate efliciently with one kind of fuel, wouldnot operate eiiciently with other kinds of fuel. Also in apparatus of this character considerable difficulty has been encountered in the formation of incrustations of fuel against the pushing faces of the secondaryram mechanism, which incrustations render the pushing faces practically useless.

More particularly, therefore, it is anobject of this invention to provide a Stoker of the above-mentioned character which is capable of efficient and continuous operation with a wide variety of fuels.

Another object is to provide a secondary ram mechanism for a horizontal reto'rt underfecd stoker which isof improved design and is extremely eiiicient in its operation.

These andother objects are effected by my invention, as will be apparent from the following description and claims `taken in 'con- `fuel through one end thereof 1928. Serial No. 283,254.

nection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a vertical sectional view of a Stoker constructed according to my inven. tion, the section being taken on the center line of the retort, and showing portions of the furnace wall;

Fig. 2 is an enlarged detail section taken on line Il -II of Fig. 1 showing the lost motion connection between the primary ram Iand the secondary ram mechanlsm;

Fig. 3 is a vertical transverse section of the stok-er shown 1n Fig. 1, the section` being takenV on the line Ill-III of Fig. 1; and,

Fig. 4 is a fragmentary plan view. According to one aspect of my invention, I provide a substantially horizontally arranged retort, which is adaptedto receive y and discharge the fuel over the'sides 'thereof and onto a laterally arranged fuel supporting grate; a primary feeding mechanism for delivering fuel into the end of the retort; and secondary ram mechanism arranged Within the lower. portions of the retort and providing a means for. supporting the fuel within the retort, and for raising the fuel over the sides of the retort in a. continuous stream of even depth. The secondary ram mechanism comprises a plurality of relatively movable plates disposed in parallel superposed stepped relation'to one another. I also provide a means `for driving the primary fuel feeding mechanism, a means for driving the uppermost of the plate-like elements, and lost motion driving connections between adjacent plate-like elements.

Referring more in detail to the construction bottom wall 14 inclined upwardly .with respect to the fuel feed (see Fig. 1).

Fuel is fed from a hopper 15 and into the end of the retort 10 by means of a primary ram 16 reciprocating within a ram box 17.

The ends of the re- The `front wall 11 of the furnace is provided with an opening 18 which receives a throatportion 19 which serves as a means for conducting the fuel from the ram box to the retort as will be readily understood..

A secondary ram mechanism 20 is arranged within the lower portion of the retort and serves as a means for supporting and propelling the fuel. The secondary ram mechanlsm comprises a plurality of relatively movable plate-like elements 21, 22, 23 and .24 arranged in parallel superposed, stepped relation to one another. The lowermost plate-like element 24 is slidably., supported by the bottom wall 14 of the retort and each of the remaining plate-like elements is slidably supported by its lower adjacent plate-like element.

These plate-like elements are ofsubstantially unlform thickness throughout their length and are provided at their rear ends with pushing faces 25, 26, 27 and 28. Each of the plate-like elements is inclined upward'- ly with respect to the fuel feed. The platelike elements are so arranged with respect to each other that the upper edges of their pushing faces fall in substantially the same planewhich plane extends longitudinally of the retort and is inclined upwardly with respect to the fuel feed. It will thus be seen that by reason of this construction, I have provided a retort of progressively decreasing depth, which construction facilitates the even feeding of the fuel over the side walls of the retort.

Overfeed grate surfaces 30, 30 extend laterally from the upper edge of the side walls 13, 13 of the retort and serveas a means for supporting and advancing the fuel during active combustion (see Fig. 3). Each of the overfeed grates comprise a plurality. of parallel arranged series of grate members. Each series comprises a plurality ofl grate members 31, 32, 33 and 34, which are pivotally connected together in end-to-end relation. The first grate member 31., considered in the direction of fuel feed, is pivotally supported, as indicated at 35, to the upper edge of the retort side Wall. The last grate member 34 of each of the series is slidably supported by a transverse member 36 supported by an I- beam 37 which is in turn supported from the furnace structure. Motion is transmitted to the lateral overfeed grates by a connecting rod 38 which is driven by an oscillating crank 39. A conventional dump grate 40 is pivotally supported adjacent the end of each overfeed grate section.

The primary ramis operated by means of a connecting rod 41 which is adapted to be lin -t-urn operated by any suitable source of power, such for instance as a conventional steam cylinder 41a (see Figs. 1 and 4). The uppermost plate-like element 21 is operated from the main ram by means of a lost-motion colinection.

As shown, the main ram is provided With a downwardly extending lug 42 which is provided with a transversely extending opening 43. A pair of parallel link 'members 44, 44

are-pivotally connected by a pin 45 to the plate-like element 21. The link members are provided at their forward ends with aligned slots.46, 46 and a series of aligned openings 47, 47. The lug 42 on the primary ram, is

arranged betweenthe link members 44, 44.

The block 49 is provided with a plurality of openings 50, 50 whleh are adapted to align with either the aligned slots 46, 46 or the aligned openings 47, 47 in the linkmembers. 'lhe block 1s held in position by means of pins 5l and 52 extending through the openy ings 50, 5() in the block, and the aligned slots 46, 46 and aligned openings 47, 47 inthe link members. 'lhe pins 4 5, 48, 51' and 52 are held` in operat-ive .position b v suitable cotter pins 53, 53.

Rearward motion of the primary ram is transmitted to the plate-like element 21 by the engagement of the pin 48 with the forward ends of the aligned slots 46, 46. The

amount of lost motiontbetween the'lug -42 and the link membersl 44, 44 is governed by the position of the block 49. The amount of lost .motion may be readily changed by removing the pins 51 and 52 .moving the block 49 to the desired. position and replacing the pins 51 and 52. 1t will thus be seen that I have provided an effective adjustable lost motion connection between the main ram and the plate-like element 2l.

It will be apparent that the movable platelike elements 2l, tion of the wall 14 which serves to support the fuel, form, in eli'ect, a retortbottom means, the component parts of which a c relatively movable for feeding the fuel longi-4 tudinally ofthe retort a nd over the side thereof. The relative movement prevents the formation of inerustations in front of. the .Tr

fuel pushing faces and provides for the even feedmg of fuel over the retort sides.

22, 23, and 24 and that por- Lost motion connections are also provided between adjacent plate-like elements of the secondary ram mechanism. As shown, the plate-like elements 22, and 24 are provided with longitudinal slots 54, and 56, respectively. 'lhe plate-like elements 2l, 22 and 23 are provided, on ltheir under sides, with blocks 57, 58 and 59, respectively. The slots 54, 55 and 56 receive the blocks 57, 58 and 59,

respectively.

Motion is transmitted between any pair of adjacent plate-like elements by means of a block engaging the ends of its respective slot. The length of any one block is less than its respective slot, thereby providing the desired lost motion connection. The blocks 57, 58 and 59 are detachably secured to their respective plate-like elements by suitable bolts 60, 60. The amount of lost motion between any two adjacent plate-like elements may be variedby removing the proper block and substituting therefor a block of greater or lesser` length, as the case might be. The bottom 14 of the retort is provided with a guide slot 61 which receives a guide block 62 which is secured to the element 24 by'bolts 63, 63.

As has beenstated, the fuelis delivered into the end of the retort .by the primary ram 16, and this fuel is advanced along the retort and over the sidel walls thereof by the vplate-like elements 21, 22, 23 and 24. It has also been stated that it is highly vdesirable that the fuelfbe fed over the Iside walls of the retort in a continuous stream of even depth. The manner in which the fuel is fed over the side walls of the retort is dependententirely upon the character of the fuel and the operative relationship existing between the primary and secondary ram elements. It is to be also noted that different fuels have different feeding characteristics.

By reason of the fact that I have provided a secondary ram mechanism which comprises a plurality of relatively movable plate-like elements whose operation with respect to the main ram andalso with respect to each other can be readily varied. I have produced an apparatus which can be operated in an eiii-v n cient manner to feed any kind/of fuel.

Also by reason of the fact that the secondary ram mechanism comprises a plurality of plate-like elements which are arranged in superposed parallel relation to one another, I am enabled to employ more ram elements and' consequentlymore pushing faces for a given length of retort; and in connecting these platelike elements by lost motion driving connections, an apparatus is produced which is extremely iexible in its operation.

In\addition, the relative movement between the plate-like elements eliminates the l formation of any incrustations in front of the pushing faces, which would seriously interfere with the .efficient operation of the Stoker.

By arranging the plate-like elements so that the upper edges of their pushing vfaces fall in substantially the same plane, which 5T plane extends longitudinally of the retort and is inclined upwardly with respect to the fuel feed, I provide a retort of progressively decreasing depth which arrangement aids set forth in the appended claims.y

What I claim is:

1. In an underfeed stoker, the. combinal tion of a retort arranged in a substantially horizontal dnection and adapted to receive fuel at one end thereof and discharge the fuel over the sides thereof; a primary feeding mechanism for delivering fuel into the fuel receivlng end of the retort; retort bottom means for supporting the fuel and including a plurality of relatively movable plate-like elements and .the movable plate-like elements providlng for the feeding of the fuel; said movable plate-like elements being constructed relatively thin and arranged in parallel, overlapping and stepped relation to one another; and means providing for the movement of the movable plate-like elements 1n substantially the longitudinal direction of the retort bottom; said last-mentioned means includijng'lost motion' drivingconnections between ad] ac ent plate-like elements; the lost motion drlvlng' connections comprising abutment members detachably secured to the movable plate-like elements and disposed within slots rovlded in adjacent plate-like elements.

2. n an underfeed stoker of the type whereln the direction of yfuel feed is first longitudlnally of a retort, thence upwardly over the sides of the retort, and thence laterally from the retort and along on. overfeed .gra-te. to an ash discharge means, the comblnation with a retort havng one end open for. the reception of fuel and the opposite endv closed; of a substantially fiat, relatively thin and w1de plate adapted to be disposedin engaging, overlapping, parallel and stepped relat1on w1th similar plates to form a fuelsupportlng and feeding means, said plate having a longitudinally-extending slot there- 1n for the reception of an abutment carried by the plate immediately thereabove to provide a lost lnotion driving connection therebetween.-

3. In an underfeed Stoker -of the type wherein the direction of ,fuel `feed is first over the sides of the retort, and thence laterv ally from the retort and along an overfeed grate to an .ash discharge means,\the com- "ination with a .retort havingone end open for the reception of fuel and the opposite end closed; of a substantially flat, relatively thin i and wide plate adapted to engage and be dis- 1.307

posed in overlappmg, parel el and stepped Kai relation with similar plates to` form a fuelsupportin and feeding means; and an` abutment xe to the underside of said plate and adapted to be disposed within a slot provided in the plate immediately therebelow to provide a lost-motion driving connection.

4. In an underfeed stoker of the t pe wherein the'direction of fuel feed is rst longitudinally of a retort, thence upwardly over the sides ofthe retort, and thence laterally from the retort and along -an overfeed grate to an ash discharge\means, the combination with a horizontally-arranged retort having one end open for the reception of fuel and the opposite end closed, and a primary feeding mechanism for delivering uel into the open end of the retort; of retort bottom In s for supporting the fuel and including a p urality of relatively movable plate-like Y elements and the movable plate-like elements providing for the feeding of the fuel; said movable plate-like elements being constructed relatively thin and arranged in parallel, overlapping, engaging, and stepped relation to one another; and means providing for the movement of the movable plate-like elements in substantially the longitudinal direction of the retort bottom; said lastmentioned means including lost-motion driving connectionsbetween adjacent plate-like elements.

5. In an underfeed stoker of the type wherein the ,direction of fuel feed is first longitudinally of a. retort, thence upwardly over the sides of the retort,` and thence laterally from the Lretort and along an overfeed grate to an ash discharge means, the combination with a retort having one end open for the reception of fuel and the`opposite end closed and comprising side walls and a bottom wall inclined upwardly with respect to theinitial direction of the fuel feed, and aprimary feeding mechanism for delivering fuel into the open end of the retort; of means disposed in the lower portions of the retort for supporting and advancing the fuel; said means comprising a. plurality of relatively movable plate-like elements arranged in parallel overlapping and stepped relation to one another; the lowermost of said plate-like elements being substantially parallel to and slida-bly supported by the bottom wall of the retort and each of the remaining plate-like elements being supported by the plate-like element immediately therebeneath; and

. means providing for the movement of the 'primary ram and the plate-like elements such that said movable plate-like elements move substantially in the longitudinal direction of theretort bottom.

. ,6. In an .underffeed Stoker. of the type wherein the direction of fuel feed is first longitudinally of a retort, thence upwardly over the sides of the retort, and thence laterally from the retort and along an overfeed gratev to an ash discharge means, the coniination With'a horizontally-arranged retort and the opposite end` closed, a primary feeding mechanism for. delivering fuel into the open' end ofthe retort; of means arranged within the lower portion of the retort'for supporting and advancing the fuel; said means comprising .a plurality of relatively movable plate-like elements having fuelpushing faces at their rear ends and being arranged in parallel, overlapping, stepped, and engaging relation to one another; the plate-like elements being inclined upwardly with respect to the initial-direction of the fuel feed and having the uppermostedges of their pushing faces arranged in substantially the same longitudinall plane, which plane is inclined upwardly with respect to the fuel feed to provide `a retort of progressively decreasing depth; and means providing for the movement of the primary feeding mechanism and the plate-like elements lsuch that said elements move in the longitudinal direction of the retort.

7. In an underfeed Stoker of the type wherein the direction of .fuel feed is first longitudinally of a retort, thence upwardly having one end open for the reception of fuel over the sides of the retort, and thence laterally from the retort and along an overfeed.

grate to an ash discharge means, the combination with a horizontally-arranged retort having one end open for the reception of fuel i and the opposite end closed and comprising side walls and a bottom wall inclined upwardly with'respect to the initial direction of the fuel feed, and a primary feeding mechanism for delivering fuel into the open end of the retort; of means disposed within the lower portions of the retort for supporting and advancing the fuel; said means comprising a plurality of relatively movable plate-like elements having fuel-pushing faces at their rear ends, and being arranged in parallel, overlapping, andstepped relation to one another; the lowermost of said platelike elements beingarranged parallel to and slidable upon the bottom wall of theretort and each of the remaining plate-like elements being supported by the plate-like element immediately therebeneatli; the plate-like elements having the upper edges of their pushing faces arranged in substantially the saine longitudinal plane, which pla-ne is inclined upwardly with respect to the initial direc-` tion of the fuel feed; a lost-motion drive connection between the primary feed mechanism and the uppermost of the plate-like elements: and lost-motion driving connections between adjacent plate-like elements.

In testimony whereof, I have hereunto subscribed my name this 24th day of May,

p DONALD J. MossHART. 

